1507P - Nivolumab-induced and radiation recall pneumonitis in patients with non-small cell lung cancer: A multicenter real world analysis of 669 patients

Abstract

BackgroundImmune checkpoint inhibitors can cause pneumonitis in lung cancer patients. The role of previous thoracic radiation therapy (TRT) as a risk factor is not clear. Furthermore, some patients show radiation recall pneumonitis (RRP) pattern. In this multicenter retrospective study, we analyzed the relationship of previous TRT and other potential risk factors with nivolumab-induced pneumonitis, and the characteristics of RRP. MethodsMedical records of non-small cell lung cancer patients, who received nivolumab between December 2015 and March 2017, were retrospectively reviewed. Baseline clinical characteristics, incidence, and risk factors were analyzed at 5 hospitals. Person’s chi-square test and multivariate logistic regression analysis (age, sex, smoking history, treatment history of TRT, and performance status at the start of nivolumab treatment) were conducted to identify potential risk factors. Imaging analysis for RRP was conducted only for patients treated in National Cancer Center Hospital at the moment. ResultsA total of 669 patients were evaluated, and the incidences of all-grade and ≥ grade 2 pneumonitis were 8.9% (60/669) and 7.2% (47/669), respectively. Two (0.3%) patients died due to the pneumonitis. Incidences of pneumonitis were 12.9% (33/256) and 6.5% (27/413) in patients with and without previous TRT, respectively. History of previous TRT was associated with pneumonitis in multivariate analysis [odds ratio, 1.95; 95% confidence interval 1.13-3.34]. Chest imaging by computed tomography of some of those patients showed RRP pattern with pneumonitis infiltration occurring in the radiation field previously treated, and the direct relation was suggested. Incidences of RRP were 4.2% (4/95) among patients with history of previous TRT and 30.8% (4/13) among patients with previous TRT and who developed nivolumab-induced pneumonitis. ConclusionsIncreasing risk of nivolumab-induced pneumonitis was associated with treatment history of TRT. RRP pattern was one of the characteristic radiographic patterns of nivolumab-induced pneumonitis in patients with previous TRT. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.